A Functional, Clinical, and Biomechanical Examination of Unicompartmental Versus Total Knee Arthroplasty for Medial Compartment Knee Osteoarthritis (FLEX-UNI): A Randomized Controlled Trial
试验速览
- 阶段
- 不适用
- 状态
- 进行中（未招募）
- 入组人数
- 40
- 试验地点
- 1
- 主要终点
- Maximum knee flexion of the operated knee during step descent
研究概览
简要总结
For patients with osteoarthritis affecting only the inner part of the knee, surgeons can offer either a partial knee replacement, which resurfaces the worn compartment alone, or a total knee replacement. Both are recommended treatments, but there is no agreement on when to choose one over the other. Partial knee replacement preserves the anterior cruciate ligament and more of the natural knee, and recovery is usually quicker, but it is used in only about one in ten knee replacements in the United Kingdom.
Studies comparing the two have mostly relied on patient questionnaires, which may not be sensitive enough to detect differences in how the knee actually functions. Studies that have measured movement directly have concentrated on level walking, which is not demanding enough to separate the two operations. Difficulty with stairs is one of the longest lasting problems patients report after knee replacement.
The FLEX-UNI trial will compare the two operations using three-dimensional motion analysis during more demanding everyday activities. Forty patients who are suitable for a partial knee replacement will be randomly allocated to receive either a partial or a total knee replacement. Patients and the researchers measuring their movement will not know which operation was performed. The main measurement is how far the operated knee bends while stepping down from a 20 cm step, measured one year after surgery. Movement during walking, stair climbing, slopes, sitting and standing, and balance will also be measured, along with questionnaires, x-rays, and complications. Results will be compared against measurements from people with healthy knees.
详细描述
FLEX-UNI is a single-centre, prospective, randomized, double-blinded, controlled superiority trial comparing medial unicompartmental knee arthroplasty (UKA) with total knee arthroplasty (TKA) in patients with anteromedial knee osteoarthritis. Forty participants will be randomized 1:1. The trial is conducted at a high-volume elective arthroplasty centre and participants are followed for 12 months.
Participants are identified from the clinic lists of participating consultant orthopaedic surgeons and screened against the eligibility criteria by a member of the research team and by the treating consultant. Following written consent and baseline assessment, participants are randomized using sequentially numbered, opaque, sealed envelopes prepared and opened by a member of the research team not involved in screening, recruitment, or outcome assessment.
Participants allocated to UKA receive a cemented medial fixed-bearing Persona Partial Knee (Zimmer Biomet, Warsaw, Indiana, USA), implanted using a spacer block technique that resurfaces the medial compartment without deliberate correction of limb alignment. Participants allocated to TKA receive a cemented Triathlon cruciate-retaining total knee system without patellar resurfacing (Stryker, Mahwah, New Jersey, USA), implanted using a measured resection technique with a mechanical alignment target. Both procedures use conventional manual instrumentation, without robotic assistance or computer navigation, and are performed by the same group of consultant surgeons, each of whom performs both operations.
Suitability for medial UKA is confirmed intraoperatively at arthrotomy in all participants, including those allocated to TKA. Participants allocated to UKA who are found at arthrotomy to be unsuitable, principally because of disease progression beyond anteromedial osteoarthritis or a deficient anterior cruciate ligament, undergo TKA.
Participants are blinded to allocation. A standard-size sterile dressing is applied to the surgical wound by an independent healthcare support worker before biomechanical testing to conceal scar length, and participants are not shown their postoperative radiographs unless there is a clinical need. Research staff performing biomechanical assessment, outcome scoring, and statistical analysis are blinded to allocation, with unblinding only after analysis is complete. The treating surgeon cannot be blinded.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
盲法说明
Participants are blinded to allocation, although those familiar with the difference in surgical incision may deduce it from the scar. A standard-size sterile dressing is applied to the wound by an independent healthcare support worker before biomechanical testing to conceal scar length, and participants are not shown postoperative radiographs unless clinically necessary. Research staff performing biomechanical assessment, outcome scoring, and statistical analysis are blinded to allocation, with unblinding only after analysis is complete. The treating surgeon cannot be blinded.
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Suitable for medial unicompartmental knee arthroplasty
- •Aged between 18 and 75 years inclusive
- •Taller than 1.5m in height (the 10th percentile for the population)
- •Functionally intact anterior cruciate ligament
- •Able to give informed consent
- •Able to return to the study centre for follow-up
- •BMI under 40
排除标准
- •Inflammatory joint disease e.g. rheumatoid arthritis
- •Previous hip procedure within the previous twelve months
- •Previous knee surgery other than arthroscopy and medial menisectomy
- •Previous ankle surgery
- •Symptomatic foot, hip or spinal pathology
- •Any medical condition limiting normal ambulation e.g. stroke, Charcot-Marie-Tooth disease, severe lymphedema, advanced cardiac disease
- •Unable to read and understand English and follow verbal and visual instructions unless they can bring a relative or friend to all study assessments to act as a translator
研究组 & 干预措施
Unicompartmental knee arthroplasty (UKA)
Description: Cemented medial fixed-bearing unicompartmental knee arthroplasty, implanted using a spacer block technique that resurfaces the medial compartment without deliberate correction of limb alignment, using conventional manual instrumentation
干预措施: Persona Partial Knee (PPK) (Device)
Total knee arthroplasty (TKA)
Cemented cruciate-retaining total knee arthroplasty without patellar resurfacing, implanted using a measured resection technique with a mechanical alignment target, using conventional manual instrumentation. This is the standard total knee implant used at the study centre.
干预措施: Triathlon cruciate-retaining total knee system. (Device)
结局指标
主要结局
Maximum knee flexion of the operated knee during step descent
时间窗: 12 months post-operatively
Peak flexion angle of the operated knee in the sagittal plane, in degrees, during descent from a 20 cm step with the operated limb acting as the trailing limb, measured using three-dimensional motion analysis.
Knee flexion
时间窗: 12 months post-operatively
Maximum knee flexion in degrees during step descent measured using movement analysis
次要结局
- Maximum knee flexion during step descent, operated limb as trailing limb(6 months post-operatively)
- Knee kinematics and kinetics(baseline, 6 months, 12 months)
- Spatiotemporal and balance(baseline, 6 months, 12 months.)
- Patient satisfaction(6 weeks, 6 months, 12 months)
- Radiographic assessment(to 12 months postoperatively)
- Complications and adverse events(to 12 months postoperatively)
- Implant survivorship(12 months)
- Intraoperative conversion from unicompartmental to total knee arthroplasty, reported as the number of participants.(day of surgery)
- Radiographic assessment of component/bone interface stability(12 months post-operatively)
- Patient satisfaction: 5 point Likert scale(12 months post-operatively)
- Survivorship(12 months)